Quantum dot-containing materials and products including same

ABSTRACT

A pre-polymer formulation comprising quantum dots and a precursor for a polymer having a free volume parameter V FH2/γ  with a value less than or equal to 0.03 cm 3 /g is disclosed. A pre-polymer formulation comprising quantum dots and a cyclohexylacrylate monomer is further disclosed. Also disclosed are a quantum dot composition including quantum dots dispersed in a polymer matrix, the quantum dot composition being prepared from a pre-polymer formulation comprising quantum dots and a precursor for a polymer having a free volume parameter V FH2/γ  with a value less than or equal to cm 3 /g; a method; and other products including a quantum dot composition described herein.

CLAIM OF PRIORITY

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/047,616, filed on 8 Sep. 2014, which is hereby incorporatedherein by reference in its entirety for all purposes.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of quantum dots, quantumdot-containing materials, and products thereof.

SUMMARY OF THE INVENTION

The present invention relates to quantum dot-containing materials andproducts thereof.

In accordance with one aspect of the present invention, there isprovided a pre-polymer formulation comprising quantum dots and aprecursor for a polymer having a free volume parameter V_(FH2/γ) with avalue less than or equal to 0.03 cm³/g.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer.

The pre-polymer formulation can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofan adhesion promoter, a photoinitiator, scatterers, a thixotrope, anemission stabilizer, and a cross-linking agent.

In accordance with another aspect of the present invention, there isprovided a pre-polymer formulation comprising quantum dots and acyclohexylacrylate monomer.

The pre-polymer formulation can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofan adhesion promoter, a photoinitiator, scatterers, a thixotrope, anemission stabilizer, and a cross-linking agent.

In accordance with a further aspect of the present invention, there isprovided a quantum dot composition including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a precursor for apolymer having a free volume parameter V_(FH2/γ) with a value less thanor equal to 0.03 cm³/g.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for polymer having a freevolume parameter V_(FH2/γ) with a value less than or equal to 0.03 cm³/gcomprises a cyclohexylacrylate monomer.

The pre-polymer formulation from which a quantum dot composition isprepared preferably further includes and adhesion promoter which becomescross-linked into the polymer matrix of the quantum dot composition.Such adhesion promoter can be incorporated into the polymer matrix in anamount up to about 10 weight percent of the quantum dot composition.Other amount outside such range may also useful. An adhesion promotercan comprise a mixture of two or more adhesion promoters. Adhesionpromoters are discussed in more detail below.

A quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer.

In accordance with another aspect of the present invention, there isprovided a quantum dot composition including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a cyclohexylacrylatemonomer.

The pre-polymer formulation comprising quantum dots and acyclohexylacrylate monomer from which such quantum dot composition isprepared preferably further includes and adhesion promoter which becomescross-linked into the resulting cyclohexylacrylate-based polymer matrixof the quantum dot composition. Such adhesion promoter can beincorporated into the cyclohexylacrylate polymer in an amount up toabout 10 weight percent of the quantum dot composition. Other amountoutside such range may also useful. An adhesion promoter can comprise amixture of two or more adhesion promoters. Adhesion promoters arediscussed in more detail below.

A quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer.

In accordance with a further aspect of the present invention, there isprovided an optical film comprising: a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, the quantum dot-containing layer including aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a precursor for a polymer havinga free volume parameter V_(FH2/γ) with a value less than or equal to0.03 cm³/g.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer.

The quantum dot composition included in the optical film can comprise aquantum dot composition within the scope of the present invention.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film. In certain preferred embodiments, each of thefirst and second substrates comprises a barrier film.

In accordance with a further aspect of the present invention, there isprovided an optical film comprising: a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, the quantum dot-containing layer including aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomer.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

The quantum dot composition included in the optical film can comprise aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomerwithin the scope of the present invention.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film. In certain preferred embodiments, each of thefirst and second substrates comprises a barrier film.

In accordance with a yet another aspect of the present invention, thereis provided an optical film comprising a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, and at least one tie layer comprising an adhesionpromoter disposed between the quantum dot-containing layer and at leastone of the first substrate and the second substrate, the quantumdot-containing layer including a quantum dot composition includingquantum dots dispersed in a polymer matrix, the quantum dot compositionbeing prepared from a pre-polymer formulation comprising quantum dotsand a precursor for a polymer having a free volume parameter V_(FH2/γ)with a value less than or equal to 0.03 cm³/g.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03comprises a cyclohexylacrylate monomer.

The quantum dot composition included in the optical film can comprise aquantum dot composition within the scope of the present invention.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film. In certain preferred embodiments, each of thefirst and second substrates comprises a barrier film.

In accordance with a yet another aspect of the present invention, thereis provided an optical film comprising a first substrate, a secondsubstrate, and a quantum dot containing layer disposed between the firstand second substrates, and at least one tie layer comprising an adhesionpromoter disposed between the quantum dot-containing layer and at leastone of the first and second substrates, the quantum dot-containing layerincluding a quantum dot composition including quantum dots dispersed ina polymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a cyclohexylacrylatemonomer.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

The quantum dot composition included in the optical film can comprise aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomerwithin the scope of the present invention.

In certain embodiments, the quantum dot-containing layer can be scaledbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film. In certain preferred embodiments, each of thefirst and second substrates comprises a barrier film.

In accordance with a yet another aspect of the present invention, thereis provided an optical component comprising a quantum dot compositionincluding quantum dots dispersed in a polymer matrix, the quantum dotcomposition being prepared from a pre-polymer formulation comprisingquantum dots and a precursor for a polymer having a free volumeparameter V_(FH2/γ) with a value less than or equal to 0.03 cm³/g, thequantum dot composition being sealed within an optically transparentmember.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2)/Y with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer.

The quantum dot composition included in the optical film can comprisethe quantum dot composition within the scope of the present invention.

In accordance with a yet another aspect of the present invention, thereis provided an optical component comprising provided a quantum dotcomposition including quantum dots dispersed in a polymer matrix, thequantum dot composition being prepared from a pre-polymer formulationcomprising quantum dots and a cyclohexylacrylate monomer, the quantumdot composition being sealed within an optically transparent member.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

The quantum dot composition included in the optical film can comprise aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomerwithin the scope of the present invention.

In accordance with yet another aspect of the present invention, there isprovided a method for curing a pre-polymer formulation comprisingquantum dots and a cyclohexylacrylate monomer, the method comprisingexposing the pre-polymer to UV radiation for more than 30 seconds.

In accordance with yet further aspect of the present invention, thereare provided displays and backlight units including a quantum dotcomposition described herein, displays and backlight units including anoptical film described herein, and displays and backlight unitsincluding an optical component described herein.

The foregoing, and other aspects described herein, all constituteembodiments of the present invention.

It should be appreciated by those persons having ordinary skill in theart(s) to which the present invention relates that any of the featuresdescribed herein in respect of any particular aspect and/or embodimentof the present invention can be combined with one or more of any of theother features of any other aspects and/or embodiments of the presentinvention described herein, with modifications as appropriate to ensurecompatibility of the combinations. Such combinations are considered tobe part of the present invention contemplated by this disclosure.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention as claimed.

Other embodiments will be apparent to those skilled in the art fromconsideration of the description and drawings, from the claims, and frompractice of the invention disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1A graphically represents adhesion (measured in pound force inch(lbf-in)) for optical films including a quantum dot-containing layerprepared from formulations as described in Examples 5-10.

FIG. 1B graphically represents edge ingress performance (measured in mm)for optical films including a quantum dot-containing layer prepared fromformulations as described in Examples 5-10.

FIG. 1C graphically represents time (in hours) from peak luminance to85% drop in peak luminance for optical films including a quantumdot-containing layer prepared from formulations as described in Examples5-10.

FIG. 2 graphically depicts the structure of an optical film describedand used for testing in the Examples.

FIG. 3A graphically represents edge ingress performance (measured in mm)for optical films including a quantum dot-containing layer prepared fromformulations as described in Examples 5-12.

FIG. 3B graphically represents time (in hours) for luminance drop to 85%of peak luminance for an optical film including a quantum dot-containinglayer prepared from formulations as described in Examples 5-12.

FIG. 3C graphically represents adhesion (measured in pound force inch(lbf-in)) for an optical film including a quantum dot-containing layerprepared from formulations as described in Examples 5-12.

FIG. 4A graphically represents edge ingress performance (measured in mm)for an optical film including a quantum dot-containing layer (including2.5 weight percent LOCTITE 3195 and 0.5 weight percentbis[2-(methyloyloxy)ethyl]phosphate (BMEP) in thecyclohexylacrylate-based polymer matrix) as a function of curing time.

FIG. 4B graphically represents time (in hours) for luminance drop to 85%of peak luminance for an optical film including a quantum dot-containinglayer (including 2.5 weight percent LOCTITE 3195 and 0.5 weight percentBMEP in the cyclohexylacrylate-based polymer matrix) as a function ofcuring time.

FIGS. 5 & 6 show schematic representations of the measurement systemreferred to in the Examples.

FIG. 7 shows an example of a configuration of crossed-BEFs.

FIG. 8 depicts a cross-sectional view of an example of an embodiment ofan optical film in accordance with one aspect of the invention.

The attached figures are simplified representations presented forpurposes of illustration only; the actual structures may differ innumerous respects, particularly including the relative scale of thearticles depicted and aspects thereof.

For a better understanding to the present invention, together with otheradvantages and capabilities thereof, reference is made to the followingdisclosure and appended claims in connection with the above-describeddrawings.

DETAILED DESCRIPTION OF THE INVENTION

Various aspects and embodiments of the present inventions will befurther described in the following detailed description.

In accordance with another aspect of the present invention, there isprovided a pre-polymer formulation comprising quantum dots and acyclohexylacrylate monomer.

Quantum dots included in a pre-polymer formulation are preferablyselected based on the desired peak emission wavelength or combinationsof wavelengths desired for the particular intend end-use application forthe pre-polymer formulation.

The total amount of quantum dots included in a pre-polymer formulationwithin the scope of the invention is preferably in a range from about0.01 to about 25 weight percent, and any weight percent in between. Forexample, an amount in a range from about 0.05 weight percent to about 15weight percent, or about 0.05 weight percent to about 5 weight percentcan be desirable for various applications. Such amounts are not intendedto be limiting. An amount outside of such ranges may also be determinedto be useful. The amount of quantum dots included in a pre-polymerformulation can vary based on the particular end application.

Quantum dots are discussed in more detail below.

The pre-polymer formulation can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofan adhesion promoter, a photoinitiator, scatterers, a thixotrope, anemission stabilizer, a cross-linking agent.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the pre-polymer formulation does not include anepoxy-containing material or other epoxy functionality.

An adhesion promoter can preferably be included in the pre-polymerformulation, for example, in an amount in the range from about 0.01weight percent to about 10 weight percent of the formulation. Otheramount outside such range may also useful. Nonlimiting exemplary amountsinclude 2.5 weight percent and 5 weight percent.

An adhesion promoter can comprise a single adhesion promoter or amixture of two or more different adhesion promoters.

An adhesion promoter can be preferably included in a pre-polymerformulation for use in applications in which adhesion of the curedformulation to a surface is desired.

A preferred example of an adhesion promoter includes, but is not limitedto, UV light curable acrylic-based optically clear adhesives, such asLOCTITE 3195, available from Henkel Corporation.

Additional examples of adhesion promoters include UV light curableacrylic-based optically clear adhesives with properties similar toLOCTITE 3195; GELEST PRIMERA 1, available from Gelest, Inc.,Morrisville, Pa. USA; bis[2-(methyloyloxy)ethyl]phosphate (BMEP),available from Sigma Aldrich, Saint Louis, Mo. USA; PL-2110 availablefrom ESSTECH, Inc., Essington, Pa. USA (a methacrylate monomer basestructure including a phosphate functionality); PL-2212 available fromESSTECH. Inc., Essington. Pa. USA (an acrylate monomer base structureincluding a carboxylate functionality); andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane). Otheradhesion promoters compatible with the quantum dots and the monomer maybe determined by the skilled artisan to be useful.

For additional information about PL-2110 and P-2112, see “AchievingAdhesion to Difficult Substrates”, by Mike J. Idacavage, published inthe September 2014 issue of Adhesives & Sealants Industry, which ishereby incorporated herein by reference.

Optionally, an adhesion promoter comprises a mixture of two or moreadhesion promoters. A non-limiting example of a mixture of adhesionpromoters includes, but is not limited to, a mixture of a UV lightcurable acrylic-based optically clear adhesive, such as LOCTITE 3195,and one or more of GELEST PRIMER A1, bis[2-(methyloyloxy)ethyl]phosphate(BMEP). PL-2110, PL-2212, andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane). Anon-limiting example of such mixture of adhesion promoters can include afirst adhesion promoter, e.g., UV light curable acrylic-based opticallyclear adhesive, such as LOCTITE 3195, in an amount of 5 weight percentbased on the pre-polymer formulation weight and from 0.05 to 0.5 weightpercent each of any one or more of other adhesion promoters included inthe mixture.

Scatterers, within the scope of the disclosure may be present, forexample, in an amount from about 0.01 weight percent to about 15 weightpercent. Amounts of scatterers outside such range may also be useful.Nonlimiting exemplary amounts include amounts in a an amount from about0.01 weight percent to about 2 weight percent, or about 0.1 weightpercent to about 1 weight percent. Examples of light scatterers (alsoreferred to herein as light scatterers, light scattering particles, orlight scattering agents) that can be used in the embodiments and aspectsof the inventions described herein, include, without limitation, metalor metal oxide particles, air bubbles, and glass and polymeric beads(solid or hollow). Other scatterers can be readily identified by thoseof ordinary skill in the art. In certain embodiments, scatterers have aspherical shape. Preferred examples of scattering particles include, butare not limited to, TiO₂, SiO₂, BaTiO₃, BaSO₄, and ZnO. Particles ofother materials that are non-reactive with the host material and thatcan increase the absorption pathlength of the excitation light in thehost material can be used. In certain embodiments, light scatterers mayhave a high index of refraction (e.g., TiO₂, BaSO₄, etc.) or a low indexof refraction (gas bubbles). Scatterers are preferably non-luminescent.

Scatterers can comprise a single type of scatterer or a mixture of twoor more different types of scatterers.

Selection of the size and size distribution of the scatterers is readilydeterminable by those of ordinary skill in the relevant art. The sizeand size distribution can be based upon the refractive index mismatch ofthe scattering particle and the cyclohexyl acrylate monomer or otherpolymer precursor in which the scatterers are to be dispersed, and thepreselected wavelength(s) to be scattered according to light scatteringtheory, e.g., Rayleigh or Mie scattering theory. The surface of thescattering particle may further be treated to improve dispersability andstability in the host material. In one embodiment, the scatteringparticle comprises TiO₂ (R902+ from DuPont) having a 0.405 μm medianparticle size and are included in a pre-polymer formulation in aconcentration in a range from about 0.01 to about 1% by weight.

The amount of the scatterers may be altered relative to the amount ofquantum dots used in the formulation. For example, when the amount ofthe scatter is increased, the amount of quantum dots may be decreased.

A pre-polymer formulation of the present invention can further include athixotrope.

A thixotrope can comprise a single thixotrope or a mixture of two ormore thixotropes.

Examples of thixotropes (which may also referred to as rheology orviscosity modifiers) which may be included in a pre-polymer formulationinclude, but are not limited to, fumed metal oxides (e.g., fumed silicawhich can be surface treated or untreated (such as CAB-O-SIL™ fumedsilica products available from Cabot Corporation, including, but notlimited to, CAB-O-SIL TS720 and CAB-O-SIL TS610), or fumed metal oxidegels (e.g., a silica gel). A pre-polymer formulation can include anamount of thixotrope in an amount greater than zero up to about 15weight percent of the pre-polymer formulation. For example, a thixotropecan be included in the formulation in an amount in a range from about 5to about 12 weight percent of the formulation. Other amounts outside therange may also be determined to be useful.

A pre-polymer formulation of the present invention can further include aphotoinitiator.

A photoinitiator can comprise a single photoinitiator or a mixture oftwo or more photoinitiators.

Nonlimiting examples of photoinitiators include IRGACURE 2022. KTO-46(Lambert), Esacure 1 (Lambert) and the like.

Photoinitiators can be included in the polymerizable formulation in anamount from about 0.01% to about 10% weight percent of the pre-polymerformulation. For example, a photoinitiator can be included in theformulation in an amount in a range from about 1 to about 5 weightpercent of the formulation. Other amounts outside the above ranges mayalso be determined to be useful.

Photoinitiators generally help to sensitize the polymerizablecomposition to UV light for photopolymerization.

A pre-polymer formulation can further include an emission stabilizer.Emission stabilizers, examples of emission stabilizers, and otherinformation concerning the use of emission stabilizers are included inInternational Application No. PCT/US2012/066151, entitled “QuantumDot-Containing Compositions Including an Emission Stabilizer, ProductsIncluding Same. And Method” of QD Vision, Inc., filed 20 Nov. 2012,which published as WO 2013/078252 on 30 May 2013, which is herebyincorporated herein by reference in its entirety.

An emission stabilizer can be included in the pre-polymer formulation inan amount greater than 0 up to about 10 weight percent of theformulation. Other amounts outside this range may also be determined tobe useful.

In many embodiments, an emission stabilizer preferably includes at leastone of potassium dodecyl phosphate and trioctyl phosphine oxide.

A pre-polymer formulation can further include a cross-linking agent.

A cross-linking agent can comprise a single cross-linking agent or amixture of two or more cross-linking agents.

Nonlimiting examples of cross-linking agents include ethylene glycoldimethacrylate EBECRYL 150 and the like.

Crosslinking agents can be included in the pre-polymer formulation in anamount from about 0.5 to about 30.0 weight percent of the pre-polymerformulation. For example, crosslinking agents can be included in thepre-polymer formulation in an amount from about 0.5 to about 15.0 weightpercent or from about 0.5 to about 3.0 weight percent of theformulation. Crosslinking agents are generally added, for example in anamount of about 1% weight percent to improve stability and strength of apolymer which helps avoid cracking of the polymer due to shrinkage uponcuring of the polymer.

A pre-polymer formulation may include no cross-linking agent.

In accordance with another aspect of the present invention, there isprovided a quantum dot composition including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a cyclohexylacrylatemonomer.

Quantum dots included in a quantum dot composition are preferablyselected based on the desired peak emission wavelength or combinationsof wavelengths desired for the particular intend end-use application forthe quantum dot composition.

The total amount of quantum dots included in a quantum dot compositionwithin the scope of the invention is preferably in a range from about0.01 to about 25 weight percent, and any weight percent in between. Forexample, an amount in a range from about 0.05 weight percent to about 15weight percent, or about 0.05 weight percent to about 5 weight percentcan be desirable for various applications. Such amounts are not intendedto be limiting. An amount outside of such ranges may also be determinedto be useful. The amount of quantum dots included in a quantum dotcomposition can vary based on the particular end application.

Quantum dots are discussed in more detail below.

The pre-polymer formulation comprising quantum dots and acyclohexylacrylate monomer from which such quantum dot composition isprepared and preferably further includes and adhesion promoter whichbecomes cross-linked into the resulting cyclohexylacrylate-based polymermatrix of the quantum dot composition. Such adhesive promoter can beincorporated into the cyclohexylacrylate polymer in an amount up toabout 10 weight percent of the quantum dot composition. Other amountoutside such range may also useful.

An adhesion promoter can comprise a single adhesion promoter or amixture of two or more different adhesion promoters.

An adhesion promoter can be preferably included in a quantum dotcomposition for use in applications in which adhesion of the curedcomposition to a surface is desired.

A preferred example of an adhesion promoter includes, but is not limitedto, UV light curable acrylic-based optically clear adhesives, such asLOCTITE 3195, available from Henkel Corporation.

Other examples of adhesion promoters include UV light curableacrylic-based optically clear adhesives with properties similar toLOCTITE 3195; GELEST PRIMER A1, available from Gelest, Inc.,Morrisville, Pa. USA; bis[2-(methyloyloxy)ethyl]phosphate (BMEP)available from Sigma Aldrich. Saint Louis, Mo. USA; PL-2110 availablefrom ESSTECH. Inc., Essington. Pa. USA, (a methacrylate monomer basestructure including a phosphate functionality); PL-2212 available fromESSTECH, Inc., Essington, Pa. USA (an acrylate monomer base structureincluding a carboxylate functionality); andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane).

Optionally, an adhesion promoter comprises a mixture of two or moreadhesion promoterss. A non-limiting example of a mixture of adhesionpromoters includes, but is not limited to, a mixture of a UV lightcurable acrylic-based optically clear adhesive, such as LOCTITE 3195,and one or more of GELEST PRIMER A1, bis[2-(methyloyloxy)ethyl]phosphate(BMEP), PL-2110, PL-2212, andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane). Anon-limiting example of such mixture of adhesion promoters can include afirst adhesion promoter, e.g., UV light curable acrylic-based opticallyclear adhesive, such as LOCTITE 3195, in an amount of 5 weight percentbased on the pre-polymer formulation weight and from 0.05 to 0.5 weightpercent each of any one or more of other adhesion promoters included inthe mixture.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

A quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

Scatterers, within the scope of the disclosure may be included, forexample, in an amount from about 0.01 weight percent to about 15 weightpercent. Amounts of scatterers outside such range may also be useful.Nonlimiting exemplary amounts include amounts in a an amount from about0.01 weight percent to about 2 weight percent, or about 0.1 weightpercent to about 1 weight percent. Examples of scatterers (which mayalso be referred to herein as light scatterers, light scatteringparticles, scattering particles, or light scattering agents) that can beused in the embodiments and aspects of the inventions described herein,include, without limitation, metal or metal oxide particles, airbubbles, and glass and polymeric beads (solid or hollow). Otherscatterers can be readily identified by those of ordinary skill in theart. In certain embodiments, scatterers have a spherical shape.Preferred examples of scattering particles include, but are not limitedto, TiO₂, SiO₂, BaTiO₃, BaSO₄, and ZnO. Particles of other materialsthat are non-reactive with the host material and that can increase theabsorption pathlength of the excitation light in the host material canbe used. In certain embodiments, light scatterers may have a high indexof refraction (e.g., TiO₂, BaSO₄, etc.) or a low index of refraction(gas bubbles). Scatterers are preferably non-luminescent ornon-emissive.

Scatterers can comprise a single type of scatterer or a mixture of twoor more different types of scatterers.

Selection of the size and size distribution of the scatterers is readilydeterminable by those of ordinary skill in the relevant art. The sizeand size distribution can be based upon the refractive index mismatch ofthe scattering particle and the cyclohexyl acrylate monomer or otherpolymer precursor in which the scatterers are to be dispersed, and thepreselected wavelength(s) to be scattered according to light scatteringtheory, e.g., Rayleigh or Mie scattering theory. The surface of thescattering particle may further be treated to improve dispensability andstability in the host material. In one embodiment, the scatteringparticle comprises TiO₂ (R902+ from DuPont) having a 0.405 μm medianparticle size and are included in a quantum dot composition in aconcentration in a range from about 0.01 to about 1% by weight.

The amount of the scatterers may be altered relative to the amount ofquantum dots used in the composition. For example, when the amount ofthe scatter is increased, the amount of quantum dots may be decreased.

A quantum dot composition of the present invention can further include athixotrope.

A thixotrope can comprise a single thixotrope or a mixture of two ormore thixotropes.

Examples of thixotropes (which may also referred to as rheology orviscosity modifiers) which may be included in a quantum dot compositioninclude, but are not limited to, fumed metal oxides (e.g., fumed silicawhich can be surface treated or untreated (such as CAB-O-SIL™ fumedsilica products available from Cabot Corporation, including, but notlimited to, CAB-O-SIL TS720 and CAB-O-SIL TS610), or fumed metal oxidegels (e.g., a silica gel). A quantum dot composition can include anamount of thixotrope in an amount greater than zero up to about 15weight percent of the quantum dot composition. For example, a thixotropecan be included in the composition in an amount in a range from about 5to about 12 weight percent of the formulation. Other amounts outside therange may also be determined to be useful.

A quantum dot composition can further include an emission stabilizer.Emission stabilizers, examples of emission stabilizers, and otherinformation concerning the use of emission stabilizers are included inInternational Application No. PCT/US2012/066151, entitled “QuantumDot-Containing Compositions Including an Emission Stabilizer. ProductsIncluding Same, And Method” of QD Vision, Inc., filed 20 Nov. 2012,which published as WO 2013/078252 on 30 May 2013, which is herebyincorporated herein by reference in its entirety.

An emission stabilizer can be included in the quantum dot composition inan amount greater than 0 up to about 10 weight percent of thecomposition. Other amounts outside this range may also be determined tobe useful.

In many embodiments, an emission stabilizer preferably includes at leastone of potassium dodecyl phosphate and trioctyl phosphine oxide.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In accordance with a further aspect of the present invention, there isprovided an optical film comprising: a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, the quantum dot-containing layer including aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomer.

FIG. 8 depicts a cross-sectional side view of an example of anembodiment of an optical film in accordance with the present invention.As shown, the optical film 1 includes a quantum dot-containing layer 20disposed between a first substrate 10 and a second substrate 30. Thefirst substrate and the second substrate can be the same or different.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

A quantum dot-containing layer can comprise a quantum dot composition inaccordance with the present invention.

The quantum dot composition included in an optical film can comprise aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomer inaccordance with an aspect of the present invention, described herein.

As provided above, the pre-polymer formulation comprising quantum dotsand a cyclohexylacrylate monomer from which such quantum dot compositionis prepared preferably further includes and adhesion promoter whichbecomes cross-linked into the resulting cyclohexylacrylate-based polymermatrix of the quantum dot composition.

Optionally, two or more adhesion promoters can also be included in thepolymer matrix by cross-linking.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, one or more of scatterers, athixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Examples of preferred substrates include glass, polycarbonate, acrylic,quartz, sapphire, a polymeric material such as plastic or silicone (e.g.but not limited to thin acrylic, epoxy, polycarbonate, PEN, PET, PE).

In certain preferred embodiments, a substrate is optically transparentto at least light having predetermined wavelengths of light passingthrough it. In certain embodiments, a substrate is at least 80%optically transparent to at least predetermined wavelengths of lightpassing through it. In certain embodiments, a substrate is at least 85%optically transparent to at least predetermined wavelengths of lightpassing through it. In certain embodiments, a substrate is at least 90%optically transparent to at least predetermined wavelengths of lightpassing through it. In certain embodiments, a substrate is at least 95%optically transparent to at least predetermined wavelengths of lightpassing through it. In certain embodiments, a substrate is at least 99%optically transparent to at least predetermined wavelengths of lightpassing through it.

The geometrical shape and dimensions of a substrate can be selectedbased on the particular end-use application.

Preferably, at least one of the first substrate and second substratecomprises a barrier film. In certain preferred embodiments, bothsubstrates comprise a barrier film.

A barrier film can be formed of any useful film material that canprotect the quantum dots from oxygen and moisture. Examples of materialsthat can be used to form a barrier film include polymers, glass ordielectric materials. More particular examples of barrier materialsinclude, but are not limited to, polymers such as polyethyleneterephthalate (PET), oxides such as silicon oxide, titanium oxide, oraluminum oxide.

A barrier film optionally comprises two or more layers, which can be thesame or different.

In certain embodiments a barrier coating can be applied to a barrierfilm.

Example of suitable barrier films or coatings include, withoutlimitation, a hard metal oxide coating, a thin glass layer, and BARIXcoating materials available from Vitex Systems. Inc. Other suitablebarrier films or coating can be readily ascertained by one of ordinaryskill in the art.

The composition of a barrier film, thickness, and number of barrierlayers will be selected based on the desired protection level for thequantum dots from oxygen and moisture as well as the intended end-useapplication.

In certain preferred embodiments, a barrier material is opticallytransparent to at least light having predetermined wavelengths of lightpassing through it. In certain embodiments, a barrier material is atleast 80% optically transparent to at least predetermined wavelengths oflight passing through it. In certain embodiments, a barrier material isat least 85% optically transparent to at least predetermined wavelengthsof light passing through it. In certain embodiments, a barrier materialis at least 90% optically transparent to at least predeterminedwavelengths of light passing through it. In certain embodiments, abarrier material is at least 95% optically transparent to at leastpredetermined wavelengths of light passing through it. In certainembodiments, a barrier material is at least 99% optically transparent toat least predetermined wavelengths of light passing through it.

In certain preferred embodiments, a barrier material does not yellow ordiscolor so as alter the optical properties of light passing through itin an undesired way.

In certain preferred embodiments, a barrier material does not partiallyor fully delaminate during the useful lifetime of the optical film.

Optionally, an optical film can include additional layers.

An optical film can further optionally include one or more lightdiffusion layers disposed between the quantum dot-containing layer andthe light-emitting surface of the optical film.

Examples of suitable commercially available light diffusion layersinclude, but are not limited to, the following light diffusion filmsavailable from KIMOTO Co. Ltd., Shinjuku Office, 1-5 Yoyogi 2-chome,Shibuya-ku, Tokyo 151-0053 JAPAN: KIMOTO Diffusion Film-Light-Up 100NSH,KIMOTO Diffusion Film-Light-Up 100MXE, KIMOTO Diffusion Film-Light-Up100SXE, KIMOTO Diffusion Film-Light-Up 100LSE, KIMOTO DiffusionFilm-Light-Up 100GM2, and KIMOTO Light Diffusion Film-Chem Mat 125PW.The KIMOTO Light Diffusion Film General Specification Sheets for theabove-listed Films being hereby incorporated herein by reference intheir entireties. Additional information concerning KIMOTO Light-UpFilms can be found in U.S. Pat. Nos. 5,831,774; 5,852,514; 5,903,391;6,592,950; 6,602,596; 6,771,335; 7,156,547; 7,244,490; and 7,525,642,which are hereby incorporated herein by reference in their entireties.Other suitable light diffusion layers can be used.

In accordance with a yet another aspect of the present invention, thereis provided an optical film comprising a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, and at least one tie layer comprising an adhesionpromoter disposed between the quantum dot-containing layer and at leastone of the first and second substrates, the quantum dot-containing layerincluding a quantum dot composition including quantum dots dispersed ina matrix comprising a cyclohexylacrylate polymer.

FIG. 8 depicts a cross-sectional side view of an example of anembodiment of an optical film in accordance with the present invention.As shown, the optical film 1 includes a quantum dot-containing layer 20disposed between a first substrate 10 and a second substrate 30. Thefirst substrate and the second substrate can be the same or different.(A tie layer is not shown in the optical film example depicted in thefigure.)

A quantum dot-containing layer can comprise a quantum dot composition inaccordance with the present invention.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

The quantum dot composition included in an optical film can comprise aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a cyclohexylacrylate monomer inaccordance with an aspect of the present invention, described herein.

A polymer matrix included in the quantum dot composition can preferablyfurther include an adhesion promoter cross-linked into the polymermatrix, as described herein.

As provided above, the pre-polymer formulation comprising quantum dotsand a cyclohexylacrylate monomer from which such quantum dot compositionis prepared preferably further includes and adhesion promoter whichbecomes cross-linked into the resulting cyclohexylacrylate-based polymermatrix of the quantum dot composition.

Optionally, two or more adhesion promoters can also be included in thepolymer matrix by cross-linking.

A tie layer can be a layer or coating comprising an adhesion promoter.

An adhesion promoter included in a tie layer can comprise an adhesionpromoter described herein. As also discussed herein, an adhesionpromoter can comprise a mixture of two or more adhesion promoters.

A tie layer comprising an adhesion promoter is preferably disposedbetween the quantum dot-containing layer and the inner-facing surface ofat least one of the substrates as a surface treatment coating on theinner-facing surface of one or both of the substrates. In certainpreferred embodiments, a tie layer comprising an adhesion promoter ispreferably disposed between the quantum dot-containing layer and theinner-facing surfaces both of the substrate as a surface treatmentcoating on the inner-facing surface of each of the first and secondsubstrates.

Preferably a tie layer is applied to a substrate or barrier film surfaceby spin-coating techniques. However, other known solution techniques canbe used to form a tie layer.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film.

In certain preferred embodiments, both substrates comprise a barrierfilm.

Substrates and barrier films are discussed in more detail above.

Optionally, an optical film can include additional layers.

An optical film can further optionally include one or more lightdiffusion layers disposed between the quantum dot-containing layer andthe light-emitting surface of the optical film.

Examples of light diffusion layers are described above.

In accordance with yet another aspect of the present invention, there isprovided an optical component including a quantum dot compositionincluding quantum dots dispersed in a polymer matrix, the quantum dotcomposition being prepared from a pre-polymer formulation comprisingquantum dots and a cyclohexylacrylate monomer, the quantum dotcomposition being sealed within an optically transparent member.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation including quantum dots and acyclohexylacrylate monomer described herein.

The quantum dot composition included in the optical component cancomprise a quantum dot composition including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a cyclohexylacrylatemonomer in accordance with an aspect of the present invention, describedherein.

As provided above, the pre-polymer formulation comprising quantum dotsand a cyclohexylacrylate monomer from which such quantum dot compositionis prepared preferably further includes and adhesion promoter whichbecomes cross-linked into the resulting cyclohexylacrylate-based polymermatrix of the quantum dot composition.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

An optically transparent member is preferably used to permit light topass into and/or out of the quantum dot composition contained therein.

An optically transparent member can have a variety of different shapesor configurations.

The member preferably includes a sealable hollow or cavity portion inwhich the quantum dot composition is disposed. Examples include a hollowtubular-like member or hollow bar-like member constructed from anoptically transparent material. A preferred material of construction forsuch member is glass.

For example, the quantum dot composition can be included in a hollow orcavity portion of a tubular-like structural member (e.g., a tube, hollowcapillary, hollow fiber, etc.) that can be open at either or both ends.Preferably open end(s) of the member are hermetically sealed after thecomposition is included therein. Examples of sealing techniques includebut are not limited to, (1) contacting an open end of a tube with anepoxy. (2) drawing the epoxy into the open end due to shrinkage actionof a curing resin, or (3) covering the open end with a glass adheringmetal such as a glass adhering solder or other glass adhering material,(4) hot glue; and (5) melting the open end by heating the glass abovethe melting point of the glass and pinching the walls together to closethe opening to form a molten glass hermetic seal.

Other suitable sealing techniques can be used for sealing the quantumdot composition in the optically transparent member, dependent upon thesize and shape of the member.

The configuration and dimensions of an optical component can be selectedbased on the intended end-use application and design.

In accordance with another aspect of the present invention, there isprovided a pre-polymer formulation comprising quantum dots and aprecursor for a polymer having a free volume parameter V_(FH2/γ) with avalue less than or equal to 0.03 cm³/g.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer. A precursor for acyclohexylacrylate polymer includes a cyclohexylacrylate monomer.

Quantum dots included in a pre-polymer formulation are preferablyselected based on the desired peak emission wavelength or combinationsof wavelengths desired for the particular intend end-use application forthe pre-polymer formulation.

The total amount of quantum dots included in a pre-polymer formulationwithin the scope of the invention is preferably in a range from about0.01 to about 25 weight percent, and any weight percent in between. Forexample, an amount in a range from about 0.05 weight percent to about 15weight percent, or about 0.05 weight percent to about 5 weight percentcan be desirable for various applications. Such amounts are not intendedto be limiting. An amount outside of such ranges may also be determinedto be useful. The amount of quantum dots included in a quantum dotpre-polymer formulation can vary based on the particular endapplication.

Quantum dots are discussed in more detail below.

The pre-polymer formulation can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofan adhesion promoter, a photoinitiator, scatterers, a thixotrope, anemission stabilizer, and a cross-linking agent.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the pre-polymer formulation does not include anepoxy-containing material or other epoxy functionality.

An adhesion promoter can be included in the pre-polymer formulation, forexample, in an amount in the range from about 0.01 weight percent toabout 10 weight percent of the formulation. Other amount outside suchrange may also useful. Nonlimiting exemplary amounts include 2.5 weightpercent and 5 weight percent.

An adhesion promoter can comprise a single adhesion promoter or amixture of two or more different adhesion promoters.

An adhesion promoter can be preferably included in a pre-polymerformulation for use in applications in which adhesion of the curedformulation to a surface is desired.

A preferred example of an adhesion promoter includes, but is not limitedto, UV light curable acrylic-based optically clear adhesives, such asLOCTITE 3195, available from Henkel Corporation.

Other examples of adhesion promoters include UV light curableacrylic-based optically clear adhesives with properties similar toLOCTITE 3195; GELEST PRIMER A1, available from Gelest. Inc.,Morrisville. Pa. USA; bis[2-(methyloyloxy)ethyl]phosphate (BMEP)available from Sigma Aldrich, Saint Louis, Mo. USA; PL-2110 availablefrom ESSTECH, Inc., Essington. Pa. USA, (a methacrylate monomer basestructure including a phosphate functionality); PL-2212 available fromESSTECH, Inc., Essington. Pa. USA (an acrylate monomer base structureincluding a carboxylate functionality); andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane).

Optionally, an adhesion promoter comprises a mixture of two or moreadhesion promoters. A non-limiting example of a mixture of adhesionpromoters includes, but is not limited to, a mixture of a UV lightcurable acrylic-based optically clear adhesive, such as LOCTITE 3195,and one or more of GELEST PRIMER A1, bis[2-(methyloyloxy)ethyl]phosphate(BMEP). PL-2110, PL-2212, andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane). Anon-limiting example of such mixture of adhesion promoters can include afirst adhesion promoter, e.g., UV light curable acrylic-based opticallyclear adhesive, such as LOCTITE 3195, in an amount of 5 weight percentbased on the pre-polymer formulation weight and from 0.05 to 0.5 weightpercent each of any one or more of other adhesion promoters included inthe mixture.

Scatterers, within the scope of the disclosure may be included, forexample, in an amount from about 0.01 weight percent to about 15 weightpercent of the pre-polymer formulation. Amounts of scatterers outsidesuch range may also be useful. Nonlimiting exemplary amounts includeamounts in a an amount from about 0.01 weight percent to about 2 weightpercent, or about 0.1 weight percent to about 1 weight percent. Examplesof scatterers that can be used in the embodiments and aspects of theinventions described herein, include, without limitation, metal or metaloxide particles, air bubbles, and glass and polymeric beads (solid orhollow). Other scatterers can be readily identified by those of ordinaryskill in the art. In certain embodiments, scatterers have a sphericalshape. Preferred examples of scattering particles include, but are notlimited to, TiO₂, SiO₂, BaTiO₃, BaSO₄, and ZnO. Particles of othermaterials that are non-reactive with the host material and that canincrease the absorption path length of the excitation light in the hostmaterial can be used. In certain embodiments, light scatterers may havea high index of refraction (e.g., TiO₂, BaSO₄, etc.) or a low index ofrefraction (gas bubbles). Scatterers are preferably non-luminescent.

Scatterers can comprise a single type of scatterer or a mixture of twoor more different types of scatterers.

Selection of the size and size distribution of the scatterers is readilydeterminable by those of ordinary skill in the relevant art. The sizeand size distribution can be based upon the refractive index mismatch ofthe scattering particle and the cyclohexyl acrylate monomer or otherpolymer precursor in which the scatterers are to be dispersed, and thepreselected wavelength(s) to be scattered according to light scatteringtheory, e.g., Rayleigh or Mie scattering theory. The surface of thescattering particle may further be treated to improve dispersability andstability in the host material. In one embodiment, the scatteringparticle comprises TiO₂ (R902+ from DuPont) having a 0.405 μm medianparticle size and are included in a pre-polymer formulation in aconcentration in a range from about 0.01 to about 1% by weight.

The amount of the scatterers may be altered relative to the amount ofquantum dots used in the formulation. For example, when the amount ofthe scatter is increased, the amount of quantum dots may be decreased.

A pre-polymer formulation of the present invention can further include athixotrope.

A thixotrope can comprise a single thixotrope or a mixture of two ormore thixotropes.

Examples of thixotropes (which may also referred to as rheology orviscosity modifiers) which may be included in a pre-polymer formulationinclude, but are not limited to, fumed metal oxides (e.g., fumed silicawhich can be surface treated or untreated (such as CAB-O-SIL™ fumedsilica products available from Cabot Corporation, including, but notlimited to, CAB-O-SIL TS720 and CAB-O-SIL TS610), or fumed metal oxidegels (e.g., a silica gel). A pre-polymer formulation can include anamount of thixotrope in an amount greater than zero up to about 15weight percent of the pre-polymer formulation. For example, a thixotropecan be included in the formulation in an amount in a range from about 5to about 12 weight percent of the formulation. Other amounts outside therange may also be determined to be useful.

A pre-polymer formulation of the present invention can further include aphotoinitiator.

A photoinitiator can comprise a single photoinitiator or a mixture oftwo or more photoinitiators.

Nonlimiting examples of photoinitiators include IRGACURE 2022, KTO-46(Lambert). Esacure 1 (Lambert) and the like.

Photoinitiators can be included in the polymerizable formulation in anamount from about 0.01% to about 10% weight percent of the pre-polymerformulation. For example, a photoinitiator can be included in theformulation in an amount in a range from about 1 to about 5 weightpercent of the formulation. Other amounts outside the above ranges mayalso be determined to be useful.

Photoinitiators generally help to sensitize the polymerizablecomposition to UV light for photopolymerization.

A pre-polymer formulation can further include an emission stabilizer.Emission stabilizers, examples of emission stabilizers, and otherinformation concerning the use of emission stabilizers are described inInternational Application No. PCT/US2012/066151, entitled “QuantumDot-Containing Compositions Including an Emission Stabilizer, ProductsIncluding Same, And Method” of QD Vision, Inc., filed 20 Nov. 2012,which published as WO 2013/078252 on 30 May 2013, which is herebyincorporated herein by reference in its entirety.

An emission stabilizer can be included in the pre-polymer formulation inan amount greater than 0 up to about 10 weight percent of theformulation. Other amounts outside this range may also be determined tobe useful.

In many embodiments, an emission stabilizer preferably includes at leastone of potassium dodecyl phosphate and trioctyl phosphine oxide.

A pre-polymer formulation can further include a cross-linking agent.

A cross-linking agent can comprise a single cross-linking agent or amixture of two or more cross-linking agents.

Nonlimiting examples of cross-linking agents include ethylene glycoldimethacrylate EBECRYL 150 and the like.

Crosslinking agents can be included in the pre-polymer formulation in anamount from about 0.5 to about 30.0 weight percent of the pre-polymerformulation. For example, crosslinking agents can be included in thepre-polymer formulation in an amount from about 0.5 to about 3.0 weightpercent or about 0.5 to about 3.0 weight percent of the formulation.Crosslinking agents are generally added, for example in an amount ofabout 1% weight percent to improve stability and strength of a polymerwhich helps avoid cracking of the polymer due to shrinkage upon curingof the polymer.

A pre-polymer formulation may include no cross-linking agent.

In accordance with a further aspect of the present invention, there isprovided a quantum dot composition including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a precursor for apolymer having a free volume parameter V_(FH2/γ) with a value less thanor equal to 0.03 cm³/g.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer. A precursor for acyclohexylacrylate polymer includes a cyclohexylacrylate monomer.

Quantum dots included in a quantum dot composition are preferablyselected based on the desired peak emission wavelength or combinationsof wavelengths desired for the particular intend end-use application forthe quantum dot composition.

The total amount of quantum dots included in a quantum dot compositionwithin the scope of the invention is preferably in a range from about0.01 to about 25 weight percent, and any weight percent in between. Forexample, an amount in a range from about 0.05 weight percent to about 15weight percent, or about 0.05 weight percent to about 5 weight percentcan be desirable for various applications. Such amounts are not intendedto be limiting. An amount outside of such ranges may also be determinedto be useful. The amount of quantum dots included in a quantum dotcomposition can vary based on the particular end application.

Quantum dots are discussed in more detail below.

The pre-polymer formulation preferably further includes and adhesionpromoter that becomes cross-linked into the polymer matrix of thequantum dot composition. Such adhesive promoter can be incorporated intothe polymer in an amount up to about 10 weight percent of the quantumdot composition. Other amount outside such range may also useful.

An adhesion promoter can comprise a single adhesion promoter or amixture of two or more different adhesion promoters.

An adhesion promoter can be preferably included in a quantum dotcomposition for use in applications in which adhesion of the curedcomposition to a surface is desired.

A preferred example of an adhesion promoter includes, but is not limitedto, UV light curable acrylic-based optically clear adhesives, such asLOCTITE 3195, available from Henkel Corporation.

Other examples of adhesion promoters include UV light curableacrylic-based optically clear adhesives with properties similar toLOCTITE 3195; GELEST PRIMER A1, available from Gelest, Inc.,Morrisville. Pa. USA; bis[2-(methyloyloxy)ethyl]phosphate (BMEP)available from Sigma Aldrich, Saint Louis. Mo. USA; PL-2110 availablefrom ESSTECH, Inc., Essington. Pa. USA, (a methacrylate monomer basestructure including a phosphate functionality); PL-2212 available fromESSTECH. Inc., Essington, Pa. USA (an acrylate monomer base structureincluding a carboxylate functionality); andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane).

Optionally, an adhesion promoter comprises a mixture of two or moreadhesion promoters. A non-limiting example of a mixture of adhesionpromoters includes, but is not limited to, a mixture of a UV lightcurable acrylic-based optically clear adhesive, such as LOCTITE 3195,and one or more of GELEST PRIMER A1, bis[2-(methyloyloxy)ethyl]phosphate(BMEP). PL-2110, PL-2212, andN-methyl-aza-2,2,4-trimethylsilacyclopentane (cyclic silazane). Anon-limiting example of such mixture of adhesion promoters can include afirst adhesion promoter, e.g., UV light curable acrylic-based opticallyclear adhesive, such as LOCTITE 3195, in an amount of 5 weight percentbased on the pre-polymer formulation weight and from 0.05 to 0.5 weightpercent each of any one or more of other adhesion promoters included inthe mixture.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

A quantum dot composition can further comprise one or more additionalcomponents, including, for example, but not limited to, one or more ofscatterers, a thixotrope, and an emission stabilizer.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

Scatterers, within the scope of the disclosure may be included, forexample, in an amount from about 0.01 weight percent to about 15 weightpercent. Amounts of scatterers outside such range may also be useful.Nonlimiting exemplary amounts include amounts in a an amount from about0.01 weight percent to about 2 weight percent, or about 0.1 weightpercent to about 1 weight percent. Examples of scatterers that can beused in the embodiments and aspects of the inventions described herein,include, without limitation, metal or metal oxide particles, airbubbles, and glass and polymeric beads (solid or hollow). Otherscatterers can be readily identified by those of ordinary skill in theart. In certain embodiments, scatterers have a spherical shape.Preferred examples of scattering particles include, but are not limitedto, TiO₂, SiO₂, BaTiO₃, BaSO₄, and ZnO. Particles of other materialsthat are non-reactive with the host material and that can increase theabsorption pathlength of the excitation light in the host material canbe used. In certain embodiments, light scatterers may have a high indexof refraction (e.g., TiO₂, BaSO₄, etc.) or a low index of refraction(gas bubbles). Scatterers are preferably non-luminescent.

Scatterers can comprise a single type of scatterer or a mixture of twoor more different types of scatterers.

Selection of the size and size distribution of the scatterers is readilydeterminable by those of ordinary skill in the relevant art. The sizeand size distribution can be based upon the refractive index mismatch ofthe scattering particle and the cyclohexyl acrylate monomer or otherpolymer precursor in which the scatterers are to be dispersed, and thepreselected wavelength(s) to be scattered according to light scatteringtheory, e.g., Rayleigh or Mie scattering theory. The surface of thescattering particle may further be treated to improve dispersability andstability in the host material. In one embodiment, the scatteringparticle comprises TiO₂ (R902+ from DuPont) having a 0.405 μm medianparticle size and are included in a quantum dot composition in aconcentration in a range from about 0.01 to about 1% by weight.

The amount of the scatterers may be altered relative to the amount ofquantum dots used in the composition. For example, when the amount ofthe scatter is increased, the amount of quantum dots may be decreased.

A quantum dot composition of the present invention can further include athixotrope.

A thixotrope can comprise a single thixotrope material or a mixture oftwo or more thixotrope materials.

Examples of thixotropes (which may also referred to as rheology orviscosity modifiers) which may be included in a quantum dot compositioninclude, but are not limited to, fumed metal oxides (e.g., fumed silicawhich can be surface treated or untreated (such as CAB-O-SIL™ fumedsilica products available from Cabot Corporation, including, but notlimited to, CAB-O-SIL TS720 and CAB-O-SIL TS610), or fumed metal oxidegels (e.g., a silica gel). A quantum dot composition can include anamount of thixotrope in an amount greater than zero up to about 15weight percent of the quantum dot composition. For example, a thixotropecan be included in the composition in an amount in a range from about 5to about 12 weight percent of the formulation. Other amounts outside therange may also be determined to be useful.

A quantum dot composition can further include an emission stabilizer.Emission stabilizers, examples of emission stabilizers, and otherinformation concerning the use of emission stabilizers are described inInternational Application No. PCT/US2012/066151, entitled “QuantumDot-Containing Compositions Including an Emission Stabilizer, ProductsIncluding Same, And Method” of QD Vision. Inc., filed 20 Nov. 2012,which published as WO 2013/078252 on 30 May 2013, which is herebyincorporated herein by reference in its entirety.

An emission stabilizer can be included in the quantum dot composition inan amount greater than 0 up to about 10 weight percent of thecomposition. Other amounts outside this range may also be determined tobe useful.

In many embodiments, an emission stabilizer preferably includes at leastone of potassium dodecyl phosphate and trioctyl phosphine oxide.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In accordance with a further aspect of the present invention, there isprovided an optical film comprising: a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstand second substrates, the quantum dot-containing layer including aquantum dot composition including quantum dots dispersed in a polymermatrix, the quantum dot composition being prepared from a pre-polymerformulation comprising quantum dots and a precursor for a polymer havinga free volume parameter V_(FH2/γ) with a value less than or equal to0.03 cm³/g.

FIG. 8 depicts a cross-sectional side view of an example of anembodiment of an optical film in accordance with the present invention.As shown, the optical film 1 includes a quantum dot-containing layer 20disposed between a first substrate 10 and a second substrate 30. Thefirst substrate and the second substrate can be the same or different.

A quantum dot-containing layer can comprise a quantum dot composition inaccordance with the present invention.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g comprises a cyclohexylacrylate monomer.

In certain preferred embodiments, a polymer matrix comprises acyclohexylacrylate-based polymer.

As provided above, the pre-polymer formulation preferably furtherincludes and adhesion promoter that becomes cross-linked into thepolymer matrix of the quantum dot composition.

While a quantum dot composition including a polymer matrix having a freevolume parameter V_(FH2/γ) with a value less than or equal to 0.03 cm³/gis desirable, the scope of the present invention also includes a quantumdot composition which is prepared from a pre-polymer formulationcomprising quantum dots and a precursor for a polymer having a freevolume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g, as taught herein, that further includes one or more additionalcomponents (e.g., but not limited to, an adhesion promoter) that becomecross-linked or otherwise incorporated into the resulting polymer matrixor quantum dot composition and provide a polymer matrix having a freevolume parameter greater than 0.03 cm³/g.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, one or more of scatterers, athixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film.

In certain preferred embodiments, both substrates comprise a barrierfilm.

Substrates and barrier films are discussed in more detail above.

Optionally, an optical film can include additional layers.

An optical film can further optionally include one or more lightdiffusion layers disposed between the quantum dot-containing layer andthe light-emitting surface of the optical film.

Examples of light diffusion layers are described above.

In accordance with a yet another aspect of the present invention, thereis provided an optical film comprising a first substrate, a secondsubstrate, and a quantum dot-containing layer disposed between the firstsubstrate and the second substrate, and at least one tie layercomprising an adhesion promoter disposed between the quantumdot-containing layer and at least one of the first and secondsubstrates, the quantum dot-containing layer including a quantum dotcomposition including quantum dots dispersed in a polymer matrix, thequantum dot composition being prepared from a pre-polymer formulationcomprising quantum dots and a precursor for a polymer having a freevolume parameter V_(FH2/γ) with a value less than or equal to 0.03cm³/g.

FIG. 8 depicts a cross-sectional side view of an example of anembodiment of an optical film in accordance with the present invention.As shown, the optical film 1 includes a quantum dot-containing layer 20disposed between a first substrate 10 and a second substrate 30. Thefirst substrate and the second substrate can be the same or different.(A tie layer is not shown in the optical film example depicted in thefigure.) A quantum dot-containing layer can comprise a quantum dotcomposition in accordance with the present invention.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a precursor for a polymer having afree volume parameter V_(FH2/γ) with a value less than or equal to 0.03comprises a cyclohexylacrylate monomer.

In certain preferred embodiments, a polymer matrix comprises acyclohexylacrylate-based polymer.

As provided above, the pre-polymer formulation preferably furtherincludes and adhesion promoter that becomes cross-linked into thepolymer matrix of the quantum dot composition.

As discussed above, a tie layer can be a layer or coating comprising anadhesion promoter.

An adhesion promoter included in a tie layer can comprise an adhesionpromoter described herein. As also discussed herein, an adhesionpromoter can comprise a mixture of two or more adhesion promoters.

A tie layer comprising an adhesion promoter is preferably disposedbetween the quantum dot-containing layer and the inner-facing surface ofat least one of the substrates as a surface treatment coating on theinner-facing surface of one or both of the substrates. In certainpreferred embodiments, a tie layer comprising an adhesion promoter ispreferably disposed between the quantum dot-containing layer and theinner-facing surfaces both of the substrate as a surface treatmentcoating on the inner-facing surface of each of the first and secondsubstrates.

Preferably a tie layer is applied to a substrate or barrier surface byspin-coating techniques.

However, other known solution techniques can be used to form a tielayer.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, one or more of scatterers, athixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot-containing layer can be sealedbetween the first and second substrates.

Preferably, at least one of the first substrate and second substratecomprises a barrier film.

In certain preferred embodiments, both substrates comprise a barrierfilm.

Substrates and barrier films are discussed in more detail above.

Optionally, an optical film can include additional layers.

An optical film can further optionally include one or more lightdiffusion layers disposed between the quantum dot-containing layer andthe light-emitting surface of the optical film.

Examples of light diffusion layers are described above.

In accordance with yet another aspect of the present invention, there isprovided an optical component including quantum dots dispersed in apolymer matrix, the quantum dot composition being prepared from apre-polymer formulation comprising quantum dots and a precursor forpolymer having a free volume parameter V_(FH2/γ) with a value less thanor equal to 0.03 cm³/g, the quantum dot composition being sealed withinan optically transparent member.

A quantum dot-containing layer can comprise a quantum dot composition inaccordance with the present invention.

In certain preferred embodiments, a quantum dot composition is preparedfrom a pre-polymer formulation described herein.

Examples of precursors for a polymer having a free volume parameterV_(FH2/γ) with a value less than or equal to 0.03 cm³/g include, forexample, but are not limited to, a cyclohexylacrylate monomer, abutylacrylate monomer, a butylmethacrylate monomer, an ethylmethacrylatemonomer, an ethylhexylmethacrylate monomer, an n-hexylmethacrylatemonomer, an isobutylacrylate monomer, or an n-octylmethacrylate monomer.

In certain preferred embodiments, a polymer matrix comprises acyclohexylacrylate-based polymer.

As provided above, the pre-polymer formulation preferably furtherincludes and adhesion promoter that becomes cross-linked into thepolymer matrix of the quantum dot composition.

In certain embodiments, an adhesion promoter does not include anepoxy-containing material or other epoxy functionality.

The quantum dot composition can further comprise one or more additionalcomponents, including, for example, one or more of scatterers, athixotrope, and an emission stabilizer, as provided above.

In certain embodiments, the additional components do not include anepoxy-containing material or other epoxy functionality.

In certain embodiments, the quantum dot composition does not include anepoxy-containing material or other epoxy functionality.

An optically transparent member is used to permit light to pass intoand/or out of the quantum dot composition contained therein.

The configuration and dimensions of an optical component can be selectedbased on the intended end-use application and design.

An optically transparent member can have a variety of different shapesor configurations.

The member preferably includes a sealable hollow or cavity portion inwhich the quantum dot composition is disposed. Examples include a hollowtubular-like member or hollow bar-like member constructed from anoptically transparent material. A preferred material of construction forsuch member is glass.

For example, the quantum dot composition can be included in a hollow orcavity portion of a tubular-like structural member (e.g., a tube, hollowcapillary, hollow fiber, etc.) that can be open at either or both ends.Preferably open end(s) of the member are hermetically sealed after thecomposition is included therein. Examples of sealing techniques includebut are not limited to, (1) contacting an open end of a tube with anepoxy. (2) drawing the epoxy into the open end due to shrinkage actionof a curing resin, or (3) covering the open end with a glass adheringmetal such as a glass adhering solder or other glass adhering material,(4) hot glue; and (5) melting the open end by heating the glass abovethe melting point of the glass and pinching the walls together to closethe opening to form a molten glass hermetic seal.

Other suitable sealing techniques can be used for sealing the quantumdot composition in the optically transparent member, dependent upon thesize and shape of the member.

In accordance with yet another aspect of the present invention, there isprovided a method for curing a pre-polymer formulation comprisingquantum dots and a cyclohexylacrylate monomer, the method comprisingexposing the pre-polymer to UV radiation for more than 30 seconds.

In accordance with yet further aspect of the present invention, thereare provided displays and backlight units including a quantum dotcomposition described herein, displays and backlight units including anoptical film described herein, and displays and backlight unitsincluding an optical component described herein.

The present invention will be further clarified by the followingexamples, which are intended to be exemplary of the present invention.

EXAMPLES Example 1 Preparation of Semiconductor Nanocrystals Capable ofEmitting Green Light

Synthesis of 475 nm CdSe Cores (ggCdSeC-424):

The following are added to an open-top 1 L steel reaction vessel:Cd(Oleate)₂ (100.97 g, 1.0 M in TOP), trioctylphosphine oxide (TOPO,53.2 g), 1-octadecylphosphonic acid (ODPA, 33.9 g) and 1-octadecene(ODE, 219 g). The vessel is subjected to 3 cycles of vacuum/nitrogen at120° C., and the temperature is raised to 270° C. under nitrogen. At270° C., a solution of 1.0 M diisobutylphosphine selenide inN-dodecylpyrrolidone (DIBP-Se, 75.2 g) is rapidly injected, within aperiod of less than 1 second, followed immediately by injection of ODE(82.5 mL between two syringes) to rapidly drop the temperature to about224° C. resulting in the production of quantum dots with an initialabsorbance peak between 420-430 nm. Immediately after the ODE injection,a solution of Cd(Oleate)₂ (237.7 g, 1.0 M in TOP) mixed with ODE (188.5g) and split into three syringes is continuously introduced along with asolution of DIBP-Se (181.5 g, 1.0 M in NDP) mixed with ODE (226.2 g) andsplit in to three syringes at a rate of 7.46 mL/min. A total of 49.4 mLof each syringe of precursor is delivered while the temperature of thereactor was maintained between 205-240° C. Energy supply for the mantleis cut at 42 mL infused and mantle removed at 45 mL infused. As theinfusion finishes, the reaction vessel is cooled rapidly by immersingthe reactor in a squalane bath chilled with liquid nitrogen to rapidlybring the temperature down to <120° C. The final material is used as iswithout further purification.

(Exemplary Properties: First absorbance peak: 475 nm, 15 nm HWHM, Totalmass: 694.3 g, Reaction yield: 89%).

Synthesis of CdSe/ZnS/CdZnS Core/Shell/Shell (ggCdSeCS-521):

The CdSe core synthesized from above, with a first absorbance peak of475 nm (39.07 mL, 6.41 mmol Cd), is mixed with dodecanethiol (15.98 g)in a syringe. All Zn(Oleate) precursors (0.5 M in trioctylphosphine) aredoped with 0.85% acetic acid by weight. A reaction flask containingZn(Oleate)₂ (98.8 g, 0.5 M in TOP) is heated to 320° C., upon which thesyringe containing cores and 1-dodecanethiol is swiftly injected. Whenthe temperature recovers to 300° C. (between 2-8 min), the precursorsare delivered via a syringe pump over a period of 40 min. The twoprecursor stocks consist of the following: 1) Zn(Oleate)₂ (198.68 g, 0.5M in TOP) mixed with Cd(Oleate)₂ (73.26 g, 1.0 M in TOP), and 2)dodecanethiol (33.53 g). During the infusion, the temperature ismaintained between 320-330° C. Any volatiles from the system are allowedto distill over and leave the system in order for the temperature toreach 320-330° C. After the infusion ended, the sample is annealed for 6min at 320-330° C. and cooled to room temperature over a period of 5-15min. The final core/shell material is precipitated via the addition ofbutanol and methanol at a 2:1 ratio v/v. The pellet is isolated viacentrifugation, and redispersed into toluene for storage.

(Exemplary Properties: Emission 541 nm+/−2 nm, FWHM 29 nm, Film EQE atRT: 102%, Film EQE at 140 C: >95%).

Example 2 Preparation of Semiconductor Nanocrystals Capable of EmittingRed Light

Synthesis of 579 nm CdSe Cores (ggCdSeC-247):

The following are added to an open-top 1 L steel reaction vessel:trioctylphosphine oxide (TOPO, 13.11 g), 1-octadecylphosphonic acid(ODPA, 1.6 g) and 1-octadecene (ODE, 191.97 g). The vessel is degassedat 100° C. until the ODE begins to reflux, backfilled with nitrogen, andthe temperature is raised to 270° C. under nitrogen. At 270° C. twosolutions, the first containing diisobutylphosphine selenide intrioctylphosphine (DIBP-Se, 3.34 g, 1.0 M in TOP) mixed with ODE (8.83g) and the second containing Cd(Oleate)₂ (4.76 g, 1.0 M in TOP) mixedwith ODE (11.32 g), are rapidly injected, within a period of less than 1second, followed immediately by injection of ODE (102.86 mL) to rapidlydrop the temperature to about 205° C. resulting in the production ofquantum dots with an initial absorbance peak between 420-430 nm.Immediately after the ODE injection, the temperature is reset to 240° C.and a solution of Cd(Oleate)₂ (90.02 g, 1.0 M in TOP) mixed with ODE(71.38 g) and split into three syringes is continuously introduced alongwith a solution of DIBP-Se (72.84 g, 1.0 M in TOP) mixed with ODE (78.52g) and split in to three syringes at a rate of 15.8 mL/min while thetemperature of the reactor is maintained between 235-245° C. At 15, 25,35 and 45 min the rate of addition is increased to 31.6, 47.3, 63.1, and84.2 mL/min respectively. A total of 45 mL (57 min 13 sec) of eachsyringe of precursor is delivered. As the infusion finishes, thereaction vessel is cooled rapidly by immersing the reactor in a squalanebath chilled with liquid nitrogen to rapidly bring the temperature downto <120° C.

The final material is used as is without further purification.

(Exemplary Properties: First absorbance peak: 579 nm, 12 nm HWHM, Totalmass: 550.40 g, Reaction yield: 63.76 mmol Cd).

Synthesis of CdSe/ZnS/CdZnS Core/Shell/Shell (grCdSeCS-740):

The reaction vessel is assembled and undergoes 3 vacuum/nitrogen cycles.Following the cycles a mixture of the CdSe core synthesized from above,with a first absorbance peak of 579 nm (744.02 g, 90 mmol Cd),Zn(Olcate)₂ (248.45 g) and 1-octadecene (ODE, 679.54 g) are addedair-free via cannula transfer. The material is degassed at 110° C. andbackfilled with nitrogen. The reaction vessel is then heated to 320° C.,upon which the syringe containing dodecanethiol (DDT, 209.65 g) isswiftly injected. At 1 min 30 sec the precursors are delivered via slowaddition over a period of 15 min. The two precursor stocks include thefollowing: 1) Zn(Oleate)₂ (236.55 g, 0.5 M in TOP) mixed withCd(Oleate)₂ (741.36 g, 1.0 M in TOP), and 2) dodecanethiol (266.99 g).During the infusion, the temperature is maintained between 320-330° C.Any volatiles from the system are allowed to distill over and leave thesystem in order for the temperature to reach 320-330° C. After theinfusion ended, the sample is annealed for 18 min at 320-330° C. andcooled to room temperature over a period of 5-15 min. The finalcore/shell material is precipitated via the addition of butanol andmethanol at a 2:1 ratio v/v. The pellet is isolated via centrifugation,and redispersed into toluene for storage.

(Exemplary Properties: Emission 628 nm+/−2 nm, FWHM 27 nm, Film EQE atRT: 94).

Example 3 Transfer of Green Quantum Dots from Solvent to MonomerSolution

100 mL of a quantum dot solution in toluene (prepared substantially asdescribed in Example 1 and with properties substantially as thosedescribed for the Green-emitting core/shell/shell CdSe/ZnS/CdZnS quantumdots so prepared) was evenly divided into 8 centrifuge tubes in an inertatmosphere box. 14.6 mL of n-butanol and 10.4 mL of methanol (bothanhydrous and oxygen free) were then sequentially added sequentially tothe tube. The centrifuge tubes were then capped and vortexed on a vortexgenie for 20 seconds. The tubes were then placed in a centrifuge andspun at 4000 rpm for 2 minutes.

The tubes were opened in the inert gas box and the centrate was pouredoff of the tubes. The tubes were inverted on a paper wiper for 2 minutesto allow any remaining centrate to drain from the tubes.

To each tube was added 10 mL of lauryl methacrylate (LMA) monomer. TheQD containing centrifuge pellet in each tube was broken up with a bluntneedle attached to a syringe barrel. The tubes were then capped andvortexed until the quantum dot pellet was redispersed. The quantumdot/monomer solutions from each centrifuge tube were then transferred toa central collection container. The empty centrifuge tubes were thenrinsed with 1-2 mL of lauryl methacrylate and the rinses combined intothe central collection container. The central collection container wascapped and wrapped with tape as a seal.

A small aliquot of the solution was removed to determine theconcentration of quantum dots by visible light absorption at 450 nmusing a UV-Vis spectrophotometer. Emission peak wavelength of thesolutions and full width half maximum of the emission lines wasdetermined using a spectrofluorimeter.

Example 4 Transfer of Red Quantum Dots from Solvent to Monomer Solution

100 mL of a quantum dot solution in toluene (prepared substantially asdescribed in Example 2 and with properties substantially as thosedescribed for the Red-emitting core/shell/shell CdSe/ZnS/CdZnS quantumdots so prepared) was evenly divided into 8 centrifuge tubes in an inertatmosphere box. 16.6 mL of n-butanol and 8.3 mL of methanol (bothanhydrous and oxygen free) were then sequentially added sequentially tothe tube. The centrifuge tubes were then capped and vortexed on a vortexgenie for 20 seconds. The tubes were then placed in a centrifuge andspun at 4000 rpm for 2 minutes.

The tubes were opened in the inert gas box and the centrate was pouredoff of the tubes. The tubes were inverted on a paper wiper for 2 minutesto allow any remaining centrate to drain from the tubes.

To each tube was added 10 mL of lauryl methacrylate monomer. The QDcontaining centrifuge pellet in each tube was broken up with a bluntneedle attached to a syringe barrel. The tubes were then capped andvortexed until the quantum dot pellet was redispersed. The quantumdot/monomer solutions from each centrifuge tube were then transferred toa central collection container. The empty centrifuge tubes were thenrinsed with 1-2 mL of lauryl methacrylate and the rinses combined intothe central collection container. The central collection container wascapped and wrapped with tape as a seal.

A small aliquot of the solution was removed to determine theconcentration of quantum dots by visible light absorption at 450 nmusing a UV-Vis spectrophotometer. Emission peak wavelength of thesolutions and full width half maximum of the emission lines wasdetermined using a spectrofluorimeter.

Example 5 Preparation of Cyclohexyl Acrylate Pre-Mix. (withCross-Linker)

A Schlenk flask equipped with a magnetic stir bar was charged with 6.0 gof CAB-O-SIL TS-720 treated fumed silica (Cabot Corporation), 26.45 g ofcyclohexyl acrylate monomer (Aldrich Chemical), and 9.9 d ofdodecanedioldimethacrylate (D₃DMA, Aldrich Chemical) was added to theflask with stirring to wet out the silica. 3.15 g of trioctylphosphineoxide, 0.32 g of dipotassium dodecyl phosphate and 10 g of additionalcyclohexyl acrylate monomer.

The Schlenk flask was then capped with a rubber septum, agitated to wetout all contents and sonicated for 30 minutes in a room temperaturewater bath/sonicator. After sonication, the septum was removed and thefluid was dispersed in the flask using a rotor-stator disperser at 9800rpm for 15 minutes.

Example 6 Preparation of Cyclohexyl Acrylate Coating Fluid. (withCross-Linker)

A Schlenk flask equipped with a magnetic stir bar was charged with 18.65g of coating fluid pre-mix and 0.82 mL of additional cyclohexyl acrylatemonomer. The flask was then sealed with a rubber septum and vacuum wascarefully applied until the flask pressure was reduced to <200 mtorr.The flask was then back filled with nitrogen and allowed to stir for twominutes. This vacuum degas procedure was repeated two additional times,leaving the coating solution under nitrogen.

The Schlenk flask containing the coating fluid was then transferred intoan inert atmosphere box and to it were added while magneticallystirring, 0.105 mL of red quantum dot/monomer solution from example 4and 0.441 mL of green quantum dot/monomer solution from example 3.

Example 7 Preparation of Laurylacrylate Pre-Mix. (with Cross-Linker)(for Comparative Example) A Schlenk flask equipped with a magnetic stirbar was charged with 6.0 g of CAB-O-SIL TS-720 treated fumed silica(Cabot Corporation), 26.45 g of laurylacrylate monomer (AldrichChemical), and 9.9 d of dodecanedioldimethacrylate (D₃DMA, AldrichChemical) was added to the flask with stirring to wet out the silica.3.15 g of trioctylphosphine oxide, 0.32 g of dipotassium dodecylphosphate and 10 g of additional laurylacrylate monomer.

The Schlenk flask was then capped with a rubber septum, agitated to wetout all contents and sonicated for 30 minutes in a room temperaturewater bath/sonicator. After sonication, the septum was removed and thefluid was dispersed in the flask using a rotor-stator disperser at 9800rpm for 15 minutes.

Example 8 Preparation of Laurylacrylate Coating Fluid. (withCross-Linker) (for Comparative Example)

A Schlenk flask equipped with a magnetic stir bar was charged with 18.65g of coating fluid pre-mix and 0.82 mL of additional laurylacrylatemonomer. The flask was then sealed with a rubber septum and vacuum wascarefully applied until the flask pressure was reduced to <200 mtorr.The flask was then back filled with nitrogen and allowed to stir for twominutes. This vacuum degas procedure was repeated two additional times,leaving the coating solution under nitrogen.

The Schlenk flask containing the coating fluid was then transferred intoan inert atmosphere box and to it were added while magneticallystirring, 0.105 mL of red quantum dot/monomer solution from example 4and 0.441 mL of green quantum dot/monomer solution from example 3.

Example 9 Preparation of Cyclohexyl Acrylate Pre-Mix. (No Cross-Linker,with LOCTITE 3195)

A Schlenk flask equipped with a magnetic stir bar was charged with 6.0 gof CAB-O-SIL TS-720 treated fumed silica (Cabot Corporation) and 35.34 gof cyclohexyl acrylate monomer (Aldrich Chemical) was added to the flaskwith stirring to wet out the silica. 3.15 g of trioctylphosphine oxide,0.32 g of dipotassium dodecyl phosphate and 10 g of additionalcyclohexyl acrylate monomer.

The Schlenk flask was then capped with a rubber septum, agitated to wetout all contents and sonicated for 30 minutes in a room temperaturewater bath/sonicator. After sonication, the septum was removed and thefluid was dispersed in the flask using a rotor-stator disperser at 9800rpm for 15 minutes.

Example 10 Preparation of Cyclohexyl Acrylate Coating Fluid. (withCross-Linker, and LOCTITE 3195)

A Schlenk flask equipped with a magnetic stir bar was charged with 15.0g of coating fluid pre-mix and 3.15 g of additional cyclohexyl acrylatemonomer and either 1.0 g (5%) or 0.5 g (2.5%) of LOCTITE 3195 (HenkelCorp.). The flask was then sealed with a rubber septum and vacuum wascarefully applied until the flask pressure was reduced to <200 mtorr.The flask was then back filled with nitrogen and allowed to stir for twominutes. This vacuum degas procedure was repeated two additional times,leaving the coating solution under nitrogen.

The Schlenk flask containing the coating fluid was then transferred intoan inert atmosphere box and to it were added while magneticallystirring, 0.105 mL of red quantum dot/monomer solution from example 4and 0.444 mL of green quantum dot/monomer solution from example 3.

Example 11 Preparation of Cyclohexyl Acrylate Pre-Mix. (for AdhesionPromoter and Cure Time Studies)

A Schlenk flask equipped with a magnetic stir bar was charged with 10 gof CAB-O-SIL TS-720 treated fumed silica (Cabot Corporation), 4.0 gLOCTITE 3195 (Henkel Corp.) and 67.534 g of cyclohexyl acrylate monomer(Aldrich Chemical) was added to the flask with stirring to wet out thesilica. 5.25 g of trioctylphosphine oxide, 0.53 g of dipotassium dodecylphosphate and 10 g of additional cyclohexyl acrylate monomer.

The Schlenk flask was then capped with a rubber septum, agitated to wetout all contents and sonicated for 30 minutes in a room temperaturewater bath/sonicator. After sonication, the septum was removed and thefluid was dispersed in the flask using a rotor-stator disperser at 9800rpm for 15 minutes.

Example 12 Preparation of Cyclohexyl Acrylate Coating Fluid. (forAdhesion Promoter and Cure Time Study)

A Schlenk flask equipped with a magnetic stir bar was charged with 9.16g of coating fluid pre-mix and 0.5 g of PL-2110 (Esstech Industries) orbis[2-(methacryloyloxy)-ethyl]phosphate (BMEP; Aldrich Corp.) as anadhesion promoter. Additional 0.08 g of cyclohexylacrylate was added tothe mixture. The flask was then sealed with a rubber septum and vacuumwas carefully applied until the flask pressure was reduced to <200mtorr. The flask was then back filled with nitrogen and allowed to stirfor two minutes. This vacuum degas procedure was repeated two additionaltimes, leaving the coating solution under nitrogen.

The Schlenk flask containing the coating fluid was then transferred intoan inert atmosphere box and to it were added while magnetically stirring0.053 mL of red quantum dot/monomer solution from example 4 and 0.2109mL of green quantum dot/monomer solution from example 3.

Example 13 Use of Adhesion Promoter as a Tie Layer

A top barrier film and bottom barrier film substrate were prepared bycutting Mitsubishi Type C barrier films into two pieces measuring 6″×4″and 7″×5″ respectively. These were taped to a glass pane with thebarrier side facing up. The glass/barrier film samples were placed on aspin coating machine. 2.0 mL of 0.5% w/w solution ofbis[2-(methacryloyloxy)-ethyl]phosphate (BMEP; Aldrich Corp.) inmethanol was flooded onto the center of the film and the unit wasimmediately spun at 2000 rpm for 1 minute. The coated film was removedfrom the spin coater and placed in a hood to air dry overnight.

Example 14 Preparation of Optical Test Films

A top barrier film and bottom barrier film substrate were prepared bycutting Mitsubishi Type C barrier films into two pieces measuring 6″×4″and 7″×5″ respectively. Two pressure sensitive adhesive films (PSA;8172EL; 3M Corp.) were cut to 5.75″×3.75″. Finally, a diffuser film (100SXE bead film; KIMOTO Tech Inc.) was cut to a 6″×4″ dimension.

The protective release layer was removed from one side of the PSA filmwhich was then laminated to the optical diffuser film using anelectrical roll laminator. Similarly, the protective release layer wasremoved from one side of the second PSA film which was then laminated tothe barrier side of the Mitsubishi top barrier film. Finally, theremaining release layer was removed from the PSA on the diffuser/PSAstack which was then laminated to the PET side (non-PSA side) of the topbarrier film/PSA stack to make an assembled upper film stack.

To prepare the coating fluid, scintillation vial equipped with a rubberseptum cap was transferred into an inert gas box and charged with 2 mLof the quantum dot coating fluid prepared in previous examples. To thiswas added 18.4 μL of IRGACURE 2022 photoinitiator. The vial was capped,shaken and removed from the glove box.

The remaining bottom barrier film substrate film was cleaned with a“lint roller” and played on the vacuum platen of an automatic bladecoater draw down machine, making sure that the barrier side of theMitsubishi Type C barrier film was facing up. A bird-type “Box” bladewas positioned on top of the barrier film making sure the correct bladewas selected to give a 5 mil (125 μm) wet film drawdown. Using apipette, the previously prepared coating solution from one scintillationvial was evenly transferred across the barrier film close to, andparallel to, the coating blade edge. The auto-drawdown machine was thenactuated drawing a smooth film of coating fluid across the barrier film.

The barrier film was removed from the vacuum platen and carefullytransferred to, and taped down to a glass plate. This assembly wasplaced in a nitrogen inerted photocuring station equipped with a D-bulbmetal halide lamp and timed shutter system. The film was allowed to sitfor 30 seconds to establish a nitrogen blanket. After this time, theshutter was opened and the film exposed to the curing light for 30seconds after which time the shutter closed (50 mW/cm² peak power, 1500mJ/cm² energy).

The thickness of the cured QD film was measured using a film micrometerand determined to be 70 μM.

To assemble the final test film, the protective release layer wasremoved from one side of the Top diffuser/barrier film stack. This wasthen laminated to the QD film side of the QD/barrier film stack using anelectrical roll laminator. The final assembled stack structure isdepicted in FIG.

Example of Adhesion Testing.

0.5 ml of pre-polymer formulation is evenly coated across the topsurface of a 2.5×3.5 piece of barrier film by using a #28 Meyer rod. Asecond piece of barrier film is coated with pre-polymer formulation bythe same method. The two pieces of coated film are then press togetherwith the coated sides of the two pieces of barrier film facing eachother, and cured for 30 seconds in a Dymax UV curing station under thesame conditions used to prepare the optical film samples (as describedabove). The resulting cured film was cut into 1 inch strips for adhesiontesting. The sample is tested using a standard T-peel protocol in anInstron. Data is analyzed MTEST Quattro software to generate the amountof force needed to initiate and propagate peeling of the adhered barrierfilms from each other.

Film Luminance. Color, and Edge Ingress Measurements Luminance and colorpoint measurements were obtained using an edge-lit configured backlightunit deconstructed from a commercially available 2013 7 inch Kindle FireHDX from which films included on the light emitting face of the lightguide plate of the backlight unit of the commercial product wereremoved; the opposite face included an enhanced specular reflector.

A test film is placed on the light emitting surface of a light guideplate. Crossed brightness enhancing films (BEFs) are positioned over thetest film, an MCET mask with a 15 mm square aperture centered in themodule is placed over the crossed-BEFS, the aperture being positionedover the position of the test film on the light guide place. A metalframe is used to hold the arrangement in place. ((BEFs) are included tomore closely simulate the conditions inside a typical display backlightunit.) After the test arrangement is assembled, the LED light strip atthe edge of light guide plate is driven at 120 milliamps constantcurrent, to illuminate the test film/crossed-BEF stack with blue (450nm) light. The light output from the light-emitting surface of the lightguide plate including the test film/crossed BEF stack is measured with aKonica Minolta CS-200 Chromameter (a luminance colorimeter (1° measuringangle (^(˜)5 mm spot size); 2° observer). Measurements were taken in thedark at room temperature.

FIG. 5 depicts an exploded view of a schematic of the backlight testingassembly used in measuring the film properties. FIG. 6 depicts aschematic backlight testing assembly with the luminance colorimeter(e.g., a Konica Minolta CS-200 Chromameter). FIG. 7 depicts an exampleof a crossed arrangement of two BEFs 1, 2 (each depicted with a prismsurface).

To perform edge-ingress measurements, a picture of the film on a flat470 nm light box (Metaphase Technologies 9×9″ 470 nm lightbox part#MB-OBL9x9-B-24) is captured using an Edmund Optics USB camera (EdmundOptics EO-1918C) equipped with a 12 mm compact fixed focal length lensand a 495 nm longpass filter to block the 470 nm light and allow thefilm emission to constitute the major part of the image. Images arecaptured using uEye camera interface and image capture software.

The image is converted to monochrome for analysis and then analyzedusing custom-developed software using the LabView software platform. Thesoftware analyzes the image to find the center of the film and thenmeasures pixel intensity as a function of distance along a straight linethrough the film center. The software then determines the intensity ofthe center area (by averaging several pixels there). The trace is thenanalyzed by the software to determine the two points that are one-halfof the center value. Using a known pixel/mm scale, the distance betweenthese two points is calculated. Subtracting this distance from the knownextents of the film and dividing by two gives the amount of ingress onone edge of the film.

Data relating to ingress of film samples for formulations as describedin Examples 5, 6, 7, 8 & 9 are depicted in FIG. 1B. The test samplesincluded no perimeter seal around the edge of the optical stack. Inother words, the layer comprising the quantum dot composition includedin the optical film included in the test stack was exposed to ambientconditions (including, e.g., air) at the edge of the stack.

Advantageously, edge ingress is reduced for samples including a quantumdot composition including a cyclohexylacrylate polymer matrix ratherthan a lauryal acrylate polymer. Such reduced ingress can result inimprovement of one or more performance properties of an optical film andan optical component including a quantum dot composition in accordancewith the present invention.

As shown in the examples, cyclohexylacrylate-based polymer improves(reduces) ingress due to its low free volume of diffusion. Edge ingressfor polycyclohexyl acrylate is reduced compared to that of polylaurylacrylate. Edge ingress for polycyclohexyl acrylate is also expected tobe lower than that for PLMA.

The free volume parameter V_(FH2/γ) values (at 298K) forpoly-cyclohexylacrylate, poly-laurylacrylate, andpoly-laurylmethacrylate are listed in the following table:

POLYMER V_(FH2)/γ @ 298 K (cm³/g) Poly-laurylmethacrylate 0.0377Poly-laurylacrylate 0.1148 Poly-cyclohexylacrylate 0.0292

Measurements of the film emission spectrum are taken using an OceanOptics USB 4000 spectrometer connected via optical fiber to acollimating lens (Ocean Optics UV-74) oriented normal to the test sampleand collecting light from the center of the sample at a distance of 118mm. Ocean Optics SpectraSuite software is used to gather data from thespectrometer, which is converted via calibration (with an Ocean OpticsLS-1 calibration lamp) to a measurement of Irradiance vs. Wavelength.For this test, the sample is mounted in a backlight testing assemblyidentical to that used for luminance and color measurements and shown inFIG. 5. A schematic of emission spectrum test assembly is shown in FIG.6.

Data obtained for ingress testing, measurements of time (in hours) forluminance drop to 85% of peak luminance, and adhesion testing for filmsprepared as described in the Examples is depicted in FIGS. 1A-1C, 3A-3C,and 4A-4B. The comparative examples included a laurylacrylate polymermatrix in which quantum dots were dispersed, prepared as described inthe Examples. The data for the comparative example samples is designatedby “LA” as the Monomer in the referenced figures. The data relating toexamples of the present invention is designed by “CHA” (cyclohexylacrylate) as the monomer in the referenced figures. In the referencedfigures, AP1 identifies test samples that included LOCTITE 3195 inpre-polymer formulation used to make the film tested, and the amount ofLOCTITE 3195 included, if any. In FIGS. 3A-3C, AP2 identifies any secondadhesion promoter included in a test sample, and “APs Method” identifieshow the second adhesion promoter was included in the film, ifapplicable. The AP2 Method designated “Additive” identifies that thesecond adhesion promoter was included in the pre-polymer formulation asan additive in addition to AP1 (LOCTITE 3195). The AP2 Method designated“Tie” identifies that the second adhesion promoter was not added to theformulation but rather spin coated onto the barrier side of the barrierfilm prior to use as described in the examples. FIGS. 4A and 4B providedata for examples of an embodiment of an optical film prepared from apre-polymer formulation, as described in the pertinent examples,including an adhesion promoter including 2.5 weight percent LOCTITE 3195and 0.5 weight percent BMEP. FIG. 4A shows ingress (in mm) for examplesof an embodiment of an optical film within the scope of the presentinvention including a quantum dot-containing layer prepared from anembodiment of a pre-polymer formulation, as described in the pertinentexamples, including a mixture of adhesion promoters (2.5 weight percentLOCTITE and 0.5 weight percent BMEP) as an additive included in theformulation (as opposed to in a tie layer)) as a function of curingtime. FIG. 4B shows time (in hours) for luminance drop to 85% of peakluminance for examples of an embodiments of an optical film within thescope of the present invention including a quantum dot-containing layerprepared from an embodiment of a pre-polymer formulation, as describedin the pertinent examples, including a mixture of adhesion promoters(2.5 weight percent LOCTITE and 0.5 weight percent BMEP) as an additiveincluded in the formulation (as opposed to in a tie layer)) as afunction of curing time.

Quantum dots (which may also be referred to herein as semiconductornanocrystals) are nanometer sized semiconductor particles that can haveoptical properties arising from quantum confinement. Quantum dotspreferably have an average particle size in a range from about 1 toabout 100 nm. In certain embodiments, quantum dots have an averageparticle size in a range from about 1 to about 20 nm (e.g., such asabout 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nm).In certain embodiments, quantum dots have an average particle size in arange from about 1 nm to about 20 nm or about 1 nm to about 10 nm.Quantum dots can have an average diameter less than about 150 Angstroms(Å). In certain embodiments, quantum dots having an average diameter ina range from about 12 to about 150 Å can be particularly desirable.However, depending upon the composition, structure, and desired emissionwavelength of the quantum dot, the average diameter may be outside ofthese ranges.

Quantum dots can have various shapes, including, but not limited to,sphere, rod, disk, other shapes, and mixtures of various shapedparticles. The particular composition(s), structure, and/or size of aquantum dot can be selected to achieve the desired wavelength of lightto be emitted from the quantum dot upon stimulation with a particularexcitation source. In essence, quantum dots may be tuned to emit lightacross the visible spectrum by changing their size. The narrow FWHM ofquantum dots can result in saturated color emission.

A quantum dot can comprise one or more semiconductor materials. Examplesof semiconductor materials that can be included in a quantum dot(including, e.g., semiconductor nanocrystal) include, but are notlimited to, a Group IV element, a Group II-VI compound, a Group II-Vcompound, a Group III-VI compound, a Group III-V compound, a Group IV-VIcompound, a Group compound, a Group II-IV-VI compound, a Group II-IV-Vcompound, an alloy including any of the foregoing, and/or a mixtureincluding any of the foregoing, including ternary and quaternarymixtures or alloys. A non-limiting list of examples include ZnO, ZnS,ZnSe, ZnTe, CdO, CdS, CdSe, CdTc, MgS, MgSe, GaAs, GaN, GaP, GaSe, GaSb,HgO, HgS, HgSe, HgTe, InAs, InN, InP, InSb, AlAs, AlN, AlP, AlSb, TlN,TlP, TlAs, TlSb, PbO, PbS, PbSe, PbTe, Ge. Si, an alloy including any ofthe foregoing, and/or a mixture including any of the foregoing,including ternary and quaternary mixtures or alloys.

In certain embodiments, quantum dots can comprise a core comprising oneor more semiconductor materials and a shell comprising one or moresemiconductor materials, wherein the shell is disposed over at least aportion, and preferably all, of the outer surface of the core. A quantumdot including a core and shell is also referred to as a “core/shell”structure.

A shell can be a semiconductor material having a composition that is thesame as or different from the composition of the core. The shell cancomprise an overcoat including one or more semiconductor materials on asurface of the core. Examples of semiconductor materials that can beincluded in a shell include, but are not limited to, a Group IV element,a Group II-VI compound, a Group II-V compound, a Group III-VI compound,a Group III-V compound, a Group IV-VI compound, a Group compound, aGroup II-IV-VI compound, a Group II-IV-V compound, alloys including anyof the foregoing, and/or mixtures including any of the foregoing,including ternary and quaternary mixtures or alloys. Examples include,but are not limited to, ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgS,MgSe, GaAs, GaN, GaP, GaSe, GaSb, HgO, HgS, HgSe, HgTe, InAs, InN, InP,InSb, AlAs, AlN, AlP, AlSb, TlN, TlP, TlAs, TlSb, PbO, PbS, PbSe, PbTc,Ge, Si, an alloy including any of the foregoing, and/or a mixtureincluding any of the foregoing. For example, ZnS, ZnSe or CdSovercoatings can be grown on CdSe or CdTe semiconductor nanocrystals.

In a core/shell quantum dot, the shell or overcoating may comprise oneor more layers. The overcoating can comprise at least one semiconductormaterial which is the same as or different from the composition of thecore. Preferably, the overcoating has a thickness from about one toabout ten monolayers. An overcoating can also have a thickness greaterthan ten monolayers. In certain embodiments, more than one overcoatingcan be included on a core. In certain embodiments, the surrounding“shell” material can have a band gap greater than the band gap of thecore material. In certain other embodiments, the surrounding shellmaterial can have a band gap less than the band gap of the corematerial.

In certain embodiments, the shell can be chosen so as to have an atomicspacing close to that of the “core” substrate. In certain otherembodiments, the shell and core materials can have the same crystalstructure.

Methods of making quantum dots are known. One example of a method ofmanufacturing a quantum dot (including, for example, but not limited to,a semiconductor nanocrystal) is a colloidal growth process. Colloidalgrowth occurs by injection an M donor and an X donor into a hotcoordinating solvent. One example of a preferred method for preparingmonodisperse quantum dots comprises pyrolysis of organometallicreagents, such as dimethyl cadmium, injected into a hot, coordinatingsolvent. This permits discrete nucleation and results in the controlledgrowth of macroscopic quantities of quantum dots. The injection producesa nucleus that can be grown in a controlled manner to form a quantumdot. The reaction mixture can be gently heated to grow and anneal thequantum dot. Both the average size and the size distribution of thequantum dots in a sample are dependent on the growth temperature. Thegrowth temperature for maintaining steady growth increases withincreasing average crystal size. Resulting quantum dots are members of apopulation of quantum dots. As a result of the discrete nucleation andcontrolled growth, the population of quantum dots that can be obtainedhas a narrow, monodisperse distribution of diameters. The monodispersedistribution of diameters can also be referred to as a “size”.

The narrow size distribution of the quantum dots (including, e.g.,semiconductor nanocrystals) allows the possibility of light emission innarrow spectral widths.

Size distribution during the growth stage of the reaction can beestimated by monitoring the absorption or emission line widths of theparticles. Modification of the reaction temperature in response tochanges in the absorption spectrum of the particles allows themaintenance of a sharp particle size distribution during growth.Reactants can be added to the nucleation solution during crystal growthto grow larger crystals.

The particle size distribution of the quantum dots (including, e.g.,semiconductor nanocrystals) can be further refined by size selectiveprecipitation with a poor solvent for the quantum dots, such asmethanol/butanol. Size selective precipitation is a known technique tothe skilled artisan.

The emission from a quantum dot capable of emitting light can be anarrow Gaussian emission band that can be tuned through the completewavelength range of the ultraviolet, visible, or infra-red regions ofthe spectrum by varying the size of the quantum dot, the composition ofthe quantum dot, or both. The narrow size distribution of a populationof quantum dots capable of emitting light can result in emission oflight in a narrow spectral range. The population can be monodisperse andpreferably exhibits less than a 15% rms (root-mean-square) deviation indiameter of such quantum dots, more preferably less than 10%, mostpreferably less than 5%. Spectral emissions in a narrow range of nogreater than about 75 nm, preferably no greater than about 60 nm, morepreferably no greater than about 40 nm, and most preferably no greaterthan about 30 nm full width at half max (FWHM) for such quantum dotsthat emit in the visible can be observed.

Quantum dots can have emission quantum efficiencies such as between 0%to greater than 95%, for example in solution. Preferably the solutionquantum efficiency is greater than 60%, 70%, 80%, or 90%.

At least a portion of the quantum dots can further include one or moreligands attached to an outer surface of a quantum dot.

Ligands can be derived from a coordinating solvent that may be includedin the reaction mixture during the growth process. Ligands can be addedto the reaction mixture. Ligands can be derived from a reagent orprecursor included in the reaction mixture for synthesizing the quantumdots. Ligands can be exchanged with ligands on the surface of a quantumdot. In certain embodiments, quantum dots can include more than one typeof ligand attached to an outer surface.

Preferably the ligands are selected to be compatible with the medium inwhich quantum dots are to be included if a dispersion of the quantumdots in the medium is desired. Such selection is within the skill of theskilled artisan.

Quantum dots included in a pre-polymer formulation, quantum dotcomposition, optical film, or optical component are preferably selectedbased on the desired peak emission wavelength or combinations ofwavelengths desired for the particular intend end-use application forthe pre-polymer formulation, quantum dot composition, optical film, oroptical component.

The total amount of quantum dots included in a pre-polymer formulationand/or quantum dot composition within the scope of the invention ispreferably in a range from about 0.01 to about 25 weight percent, andany weight percent in between. For example, an amount in a range fromabout 0.05 weight percent to about 15 weight percent, or about 0.05weight percent to about 5 weight percent can be desirable for variousapplications. An amount outside of such ranges may also be determined tobe useful. The amount of quantum dots included in a pre-polymerformulation or a quantum dot composition can vary based on theparticular end application.

When quantum dots that emit light with peak emission wavelengths thatdiffer from that of other quantum dots included in a particularembodiments, the amounts of each are selected based on the desired lightout-put. Such determination can be readily made by the person ofordinary skill in the relevant art. For example, the ratio of quantumdots with different peak emissions that are used in a pre-polymerformulation and/or quantum dot composition is determined by the emissionpeaks of the quantum dots used. For example, when quantum dots capableof emitting green light having a peak center wavelength in a range fromabout 514 nm to about 540 nm, and any wavelength in between whetheroverlapping or not, and quantum dots capable of emitting red lighthaving a peak center wavelength in a range from about 615 nm to about640 nm, and any wavelength in between whether overlapping or not, areused in pre-polymer formulation and/or quantum dot composition, theratio of the weight percent green-emitting quantum dots to the weightpercent of red-emitting quantum dots can be in a range from about 12:1to about 1:1, and any ratio in between whether overlapping or not.

In certain embodiments of the present invention, quantum dots that emitwavelengths characteristic of red light are desirable. In certainpreferred embodiments, quantum dots capable of emitting red light emitlight having a peak center wavelength in a range from about 615 nm toabout 635 nm, and any wavelength in between whether overlapping or not.For example, the quantum dots can be capable or emitting red lighthaving a peak center wavelength of about 630 nm, of about 625 nm, ofabout 620 nm, of about 615 nm.

In certain embodiments of the present invention, quantum dots that emitwavelength characteristic of green light are desirable. In certainpreferred embodiments, quantum dots capable of emitting green light emitlight having a peak center wavelength in a range from about 520 nm toabout 545 nm, and any wavelength in between whether overlapping or not.For example, the quantum dots can be capable or emitting green lighthaving a peak center wavelength of about 520 nm, of about 525 nm, ofabout 535 nm, of about 540 nm.

Quantum dots (including, but not limited to, semiconductor nanocrystals)are preferably handled in a controlled (oxygen-free and moisture-free)environment, preventing the quenching of luminescent efficiency duringthe fabrication process.

Other materials, techniques, methods, applications, and information thatmay be useful with the present invention are described in: InternationalPublication No. WO 2011/047385, published 21 Apr. 2011, of QD Vision,Inc. entitled “An Optical Component, Products Including Same, andMethods For Making Same”; International Publication No. WO 2009/151515A1, published 17 Dec. 2009, of QD Vision, Inc., entitled “Solid StateLighting Devices Including Quantum Confined SemiconductorNanoparticles”; International Publication No. WO 2013/078249 A1,published 30 May 2013, of QD Vision, Inc., entitled “Method of MakingQuantum Dots”; International Publication No. WO 2013/122819 A1,published 22 Aug. 2013, of QD Vision. Inc., entitled “Method of MakingComponents Including Quantum Dots, Methods, and Products”; InternationalPublication No. WO 2013/122820 A1, published 22 Aug. 2013, of QD Vision,Inc., entitled “Method of Processing Quantum Dot Inks”; InternationalPublication No. WO 2014/018090 A1, published 30 Jan. 2014, of QD Vision.Inc., entitled “Method of Making Components Including Quantum Dots.Methods, and Products”; International Publication No. WO 2013/078242 A1,published 30 May 2013, of QD Vision. Inc., entitled “Methods For CoatingSemiconductor Nanocrystals”; International Publication No. WO2013/078245 A1, published 30 May 2013, of QD Vision. Inc., entitled“Method of Making Quantum Dots”; International Publication No. WO2013/078247 A1, published 30 May 2013, of QD Vision, Inc., entitled“Methods of Coating Semiconductor Nanocrystals, SemiconductorNanocrystals, and Products Including Same”; U.S. Publication No.2013/0148376 A1, published 13 Jun. 2013, of QD Vision. Inc., entitled“Stress-Resistant Component For Use With Quantum Dots”; and U.S.Publication No. 2012/0113671 A1, published 10 May 2012, of QD Vision,Inc., entitled “Quantum Dot Based Lighting”, and U.S. Pat. No.8,718,437, issued 6 May 2014, of Coe-Sullivan, et al., entitled“Compositions, Optical Component. System Including An Optical Component.Devices, And Other Products”, each of the foregoing being herebyincorporated herein by reference in its entirety.

As used herein, the singular forms “a”, “an” and “the” include pluralunless the context clearly dictates otherwise. Thus, for example,reference to an emissive material includes reference to one or more ofsuch materials.

Applicants specifically incorporate the entire contents of all citedreferences in this disclosure. Further, when an amount, concentration,or other value or parameter is given as either a range, preferred range,or a list of upper preferable values and lower preferable values, thisis to be understood as specifically disclosing all ranges formed fromany pair of any upper range limit or preferred value and any lower rangelimit or preferred value, regardless of whether ranges are separatelydisclosed. Where a range of numerical values is recited herein, unlessotherwise stated, the range is intended to include the endpointsthereof, and all integers and fractions within the range. It is notintended that the scope of the invention be limited to the specificvalues recited when defining a range.

Other embodiments of the present invention will be apparent to thoseskilled in the art from consideration of the present specification andpractice of the present invention disclosed herein. It is intended thatthe present specification and examples be considered as exemplary onlywith a true scope and spirit of the invention being indicated by thefollowing claims and equivalents thereof.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A pre-polymer formulation comprising: quantumdots; an adhesion promoter, wherein the adhesion promoter comprises a UVlight curable optically transparent acrylic based material havingadhesive properties; and a cyclohexylacrylate monomer.
 2. A pre-polymerformulation in accordance with claim 1 wherein the UV light curableoptically transparent acrylic based material a comprisesbis[2-(methyloyloxy)ethyl]phosphate.
 3. A pre-polymer formulation inaccordance with claim 1 wherein the UV light curable opticallytransparent acrylic based material comprises a methacrylate monomer basestructure including a phosphate functionality.
 4. A pre-polymerformulation in accordance with claim 1 wherein the UV light curableoptically transparent acrylic based material comprises an acrylatemonomer base structure including a carboxylate functionality.
 5. Apre-polymer formulation in accordance with claim 1 wherein theformulation includes the adhesion promoter in an amount greater than 0up to about 10 weight percent of the formulation.
 6. A pre-polymerformulation in accordance with claim 1 further comprising scatterers. 7.A pre-polymer formulation in accordance with claim 6 wherein theformulation includes the scatterers in an amount of 0.01 to about 15weight percent of the formulation.
 8. A pre-polymer formulation inaccordance with claim 1 further comprising a thixotrope.
 9. Apre-polymer formulation in accordance with claim 8 wherein theformulation includes the thixotrope in an amount greater than 0 up toabout 15 weight percent of the formulation.
 10. A pre-polymerformulation in accordance with claim 1 further comprising aphotoinitiator.
 11. A pre-polymer formulation in accordance with claim10 wherein formulation includes the photoinitiator in an amount of about0.01 to about 10 weight percent of the formulation.
 12. A pre-polymerformulation in accordance with claim 1 wherein formulation includesquantum dots in an amount of about 0.01 to about 25 weight percent ofthe formulation.
 13. A pre-polymer formulation in accordance with claim1 further comprising an emission stabilizer.
 14. A pre-polymerformulation in accordance with claim 13 wherein the emission stabilizercomprises at least one of potassium dodecyl phosphate and trioctylphosphine oxide.
 15. A pre-polymer formulation in accordance with claim13 wherein the formulation includes the emission stabilizer in an amountgreater than 0 up to about 10 weight percent of the formulation.
 16. Apre-polymer formulation in accordance with claim 1 further including across-linking agent.
 17. A pre-polymer formulation in accordance withclaim 16 wherein the formulation includes the cross-linking agent in anamount of about 0.5 to about 15 weight percent of the formulation.